This invention relates to optical fiber wave-guiding structures and, more particularly, to a new technique and apparatus for group splicing optical fiber waveguides.
Optical fiber waveguides are considered as potential replacements for wire pairs, coaxial cable and metallic waveguides in many systems involving the transmission of information and control signals from one point to another. The advantages of fiber systems over conventional systems include the small physical size and light weight of the fibers, the broad bandwidth capabilities which afford flexibility in the selection of a bandwidth to be utilized in any given system, the nonconductive, noninductive properties of the fibers, and the potentially low cost of fiber materials and fabrication. It is generally recognized that a prerequisite to the eventual success of fiber systems is the development of reliable and simple fiber splicing arrangements. It is evident that, to be practical, any technique for splicing fibers must not only be quick and convenient to perform, but must also achieve the ultimate goal of transferring the optical signal power from one fiber to another with a minimum amount of loss at the splice.
Because of the small size of optical fibers (fiber diameters typically range from several micrometers to several mils in size), it is generally considered preferable to be able to handle and splice fibers in groups or bundles, rather than on an individual basis. Optical fiber ribbons are typical group fiber structures in which two or more fiber waveguides are embedded in spaced-apart positions parallel to each other in a ribbon-like outer jacket or sheathing. Numerous techniques and arrangements have been proposed in the art for splicing fiber groups like the fiber ribbon. One of the simplest and more accurate arrangements for aligning the fibers for group splicing involves the use of a chip or wafer with accurately spaced, prefabricated grooves in which the fibers are positioned. Unfortunately, with such arrangements, it has been found that it is difficult to keep the fiber ends clean during the various steps leading from the fiber end preparation for splicing to the final fiber alignment and connection. Particularly, the technique of sliding the fibers into the grooves from both ends of the wafer is likely to contaminate the fiber ends, either by picking up dust particles or other contamination present in the grooves, or by chafing material off the side walls of the grooves. Such end face contamination can greatly increase the optical power loss at the region of the splice.